Part of what makes Pathfinder Society so successful, is that they have such a wide backlog of scenarios to draw from. There are 5 seasons of modules (0,1,2,3,4) and the current, season 5. With 5th ed now, Not having the previous missions as "New to you" for new players makes the available scenario pool a bit shallow. I know the campaigns are structured differently (ie, SRM tries to tell a coherent story over a season and PFS really doesn't so much) but just throwing it out there.
The reason I am attracted to the "Missions" or "Pathfinder Society" format as a GM, is that I really appreciate the 4hr design of the modules, as well as the ability to easily drop in / drop out players. I'm actually thinking about going through some of the old Season 1 SRM modules and converting them to 5th ed just for fun/exercise in rules learning.
Was there a season 0? Are those modules available?
And, For what its worth, Pathfinder Society has to deal with level ranges etc up to level 12...they publish 2 scenarios a month, and still have people crying for more.